Simple hydrolysis-photodeposition route to synthesize Ag/BiOCl0.5Br0.5 composites with highly enhanced visible-light photocatalytic properties

•A simple hydrolysis-photodeposition route to synthesize Ag/BiOCl0.5Br0.5 composites.•Synergistic effect of Ag and BiOCl0.5Br0.5 enhances efficient separation of carriers.•Ag/BiOCl0.5Br0.5 has excellent visible-light photocatalytic activity and stability.•Charge-transport mechanism, effective separation of photoinduced electron–hole pairs.•Such Ag-decorated BiOX0.5X″0.5 system has promising application in photocatalysis.

A series of Ag/BiOCl0.5Br0.5 photocatalysts with different Ag contents were synthesized via a simple hydrolysis-photodeposition method. As-prepared products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectra (DRS). The photocatalytic activities of Ag/BiOCl0.5Br0.5 composites were evaluated by the degradation of Methyl orange (MO) dye pollution and phenol non-dye pollution under visible-light (λ > 420 nm) irradiation. Results reveal that Ag/BiOCl0.5Br0.5 composites have much higher photocatalytic activities than pure BiOCl0.5Br0.5 and commercial TiO2 (P25), that 1%-Ag/BiOCl0.5Br0.5 exhibits the highest photocatalytic activity and stability. The enhanced performance could be ascribed to the roles of Ag Nanoparticles (NPs) as electron traps and the surface plasma resonance effect, achieving the more effective charge transfer and separation derived from the Schottky barriers between Ag NPs and BiOCl0.5Br0.5 nanosheets. Finally, main active species and enhanced photocatalytic mechanism of Ag/BiOCl0.5Br0.5 were investigated.

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